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Coordination Electronically of Cyclic/Collective/Anti-Torque Pedals


LJS1993

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Okay gentleman considering the technology that is available how long do you think it will take to have a helicopter produced which "simplifies" the controls of flight. Perhaps a computer system that would perhaps synchronize phases of flight thus eliminating the need for perhaps one control? Is this unrealistic at this time?

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Why? Sometimes I want, no- need to, must! cross-control. Look at airplanes- the Ercoupe did without pedals. Wasn't exactly a run-away best seller without'em. And it was sold as spin proof.

 

Once you learn to fly with all the controls, it's as automatic walking upright. And sometimes you want to do more than just walk.

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Even the most automated of automated airplanes have a control for nose up/down, roll left/right and yaw left/right for balance.

 

Some autopilot features will compensate for yaw during a power application, and others will fix a pitch movement with power, but these are just to maintain a specific flight condition. There are also mechanical interlinks to correct the pitch with power and also yaw/roll - such as in choppers with tilted tail rotors.

 

When you want to change the condition, you need a control.

 

They have tried a single hand control for pitch, roll, power and yaw, but found that there were too many ergonomic cross-control effects to be useful. That is, it was hard to roll without twisting it (yaw) and hard to twist without lifting it (power) and so on.

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I don't know that it's entirely a question of lack of technology... afterall traditional helicopters have been entirely automated.

To some degree perhaps its (variably) inevitable. The actual pilots (not just wannabes like myself) here seem to suggest there are conditions where you would want to fly outside of the flight envelope you suggest that would exist with simplified controls. That said, it seems even completely mechanical helicopters can be controlled with great accuracy by a decent pilot. I know the pilot who took me up for my R22 lesson made that thing do stuff I never realized was possible. That said, stability augmentation seems to be a popular thing on many helicopters, and in the fixed wing world certain aircraft can't, to my knowledge, even be physically controllable by a human without computer augmentation. That doesn't mean anyone can fly an F22 and fly it well, for example.

 

EricHunt, was the RAH-66 the only helicopter to integrate anti-torque control into a side stick? Was that found to be unworkable? Just curious. I know there was also a conceptual control that integrated vertical movement of the cyclic as collective control, and rotational input as yaw control. That just seemed dumb. I do think as FBW becomes more popular side-sticks will as well. I believe the V-280 operates with a side-stick as did the Sikorsky X2. Sorry... rambling off-topic.

 

Mike

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Mike, the new Bell 525 has 2 sidesticks, set into the armrests of the pilot seat, but from the pictures, there are also pedals.

 

So, it would appear that the sticks are still for cyclic in right hand and collective in left hand, but it is all FBW after that. It would be weird not to have a stick between the knees after all these years, it would make me feel like Captain Kirk on his bridge.

 

Dunno about the RAH-66 (is that the attack version of the R-66??) as I left the military well before that one appeared.

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Okay gentleman considering the technology that is available how long do you think it will take to have a helicopter produced which "simplifies" the controls of flight. Perhaps a computer system that would perhaps synchronize phases of flight thus eliminating the need for perhaps one control? Is this unrealistic at this time?

I don’t see how that would work well. How would the aircraft know if I want 100% torque at 20ft level flight above the trees for max speed or 100% torque for max climb? I want and need independent controls to operate the helicopter. There are some computer driven aids for reducing torque spikes in uncompensated maneuvering but those are pretty much bandaids for poor control touch or emergency conditions.

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Mike, the new Bell 525 has 2 sidesticks, set into the armrests of the pilot seat, but from the pictures, there are also pedals.

 

So, it would appear that the sticks are still for cyclic in right hand and collective in left hand, but it is all FBW after that. It would be weird not to have a stick between the knees after all these years, it would make me feel like Captain Kirk on his bridge.

 

Dunno about the RAH-66 (is that the attack version of the R-66??) as I left the military well before that one appeared.

Ah that was the comanche concept. They didn't have pedals and it was incorporated into the sidestick

 

Here is another interesting article on 4-axis controllers in helicopters

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940008832.pdf

 

Mike

 

 

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So it's not completely ridiculous in thought and has been attempted or considered. Overall guys has innovation come that far in helicopters from let's say the fifties/sixties in terms of overall basic controls/coordination? I know turbine power of course but what about overall controls?

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Fly-by-wire is huge. The actual pilots can chime in, but when you talk about fixed wing we have aircraft that cannot be flown without computer aided decision making based off pilot input. Just look at the combinations of control surfaces and thrust vectoring on fighters.I seem to recall tilt-rotor platforms like the Osprey also being unflyable if not for computer augmentation, especially as the control parameters are blended from full "helicopter" mode to "airplane" mode. The cyclic transitions from controlling the rotor disks to controlling control surfaces on the aircraft, and the collective is treated as a "thrust control lever," and everything in between as they make the transition.

 

As to traditional helicopters, there are various degrees of control via flight directors and stability augmentation, and I'm sure some of the actual pilots will be able to better elaborate. Obviously the fully autonomous helicopters they have computers take care of the "flying" part themselves. The input from the ground is not cyclic, collective, anti-torque, but rather a plotted course.

I think it should be noted that there is a distinction between using a 4-axis control and using a control layout as you describe. The controller linked in the NASA article, while reliant on fly-by-wire, could conceivably be used with zero computer augmention. All the traditional helicopter controls are there: Collective, anti-torque, and cyclic. It sounds like you are thinking of something more like the traditional controls, but with the caveat that the computer compensates for the interaction between them... IE Collective = Up-Down. Cyclic = left-right/forward-back. Pedals = yaw, with a computer negating the need to adjust any other controls accordingly. I'm sure it's possible... I guess the question is just whether or not it's necessary. Some of the pilots here seem to think they would lose some control authority that they like in such a setup, and since helicopters can be flown well the way they are, why bother? I do think having the ability to "activate" varying degrees of automation to reduce pilot workload makes sense, but then again, helicopters are already doing that.

 

Disclaimer: I'm a law student and merely an (aspiring) pilot. Just a bit of an aerospace nerd so I've looked into this stuff.

 

Mike

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There are plenty of computer aided functions in my helicopter but they all are supporting the pilot’s input via the traditional mechanical controls. The FMC has stability augmentation which allows a limited amount of blade pitch adjustments indepentant of pilot input but solely to maintain the aircraft in the state the pilot intended. Example, hovering with a variable wind the stability augmentation helps to maintain a stable platform on its own. We have command augmentation which uses computer signals to initiate control servo movement faster than the mechanical linkages that actually connect the controls to the servos. It’s not fly-by-wire, just a system to reduce the delay between inputs and response to the absolute minimum.

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but what about overall controls?

 

LJS, we need to control the machine in pitch (for airspeed), roll (for direction) and yaw (for balance or to turn in the hover) plus control power. Basically three controls, plus a throttle / engine governor. One for each hand, one for each foot. And a lot of the time we can take the left hand off its control to play with radios, screens, Yoochoob, Netflix, whatever.

 

How many do you want to eliminate?

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LJS, we need to control the machine in pitch (for airspeed), roll (for direction) and yaw (for balance or to turn in the hover) plus control power. Basically three controls, plus a throttle / engine governor. One for each hand, one for each foot. And a lot of the time we can take the left hand off its control to play with radios, screens, Yoochoob, Netflix, whatever.

 

How many do you want to eliminate?

Well which one is the most possible to be taken care of by some kind of synchro? Also with all that time to use your left hand you mean to tell me you never bump some Magnum PI theme song?

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Well which one is the most possible to be taken care of by some kind of synchro? Also with all that time to use your left hand you mean to tell me you never bump some Magnum PI theme song?

 

Helicopters aren't airplane, automation is going to be much more involved than just fly-by-wire takeoff to touchdown on a runway. Perhaps half the time you're operating in a predictable defined environment, the other half you're down in amongst the obstacles. Now you're talking about more than wiggling sticks, you have to see and anticipate stuff that as far as I know most sensors won't even pick up.

 

I can see automation taking over all the controls a great deal of the time, but there are times that it's best to not do the controls coordinated thing: suppose you're landing on a site with lots of obstacles, you want to come in sideways to see everything? Seems to me that I can put the skids down pretty accurately through the bubble, but the tail rotor is way back there, I want to see as much as in can before move the TR into an area of potential strike.

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Helicopters aren't airplane, automation is going to be much more involved than just fly-by-wire takeoff to touchdown on a runway. Perhaps half the time you're operating in a predictable defined environment, the other half you're down in amongst the obstacles. Now you're talking about more than wiggling sticks, you have to see and anticipate stuff that as far as I know most sensors won't even pick up.

 

I can see automation taking over all the controls a great deal of the time, but there are times that it's best to not do the controls coordinated thing: suppose you're landing on a site with lots of obstacles, you want to come in sideways to see everything? Seems to me that I can put the skids down pretty accurately through the bubble, but the tail rotor is way back there, I want to see as much as in can before move the TR into an area of potential strike.

 

While these are great points I can see a LIDAR array and some powerful computers taking care of most of these issues. Yeah the tail rotor is way back where obstacles might me, but not hard to have a computer account for that.

 

I think part of the reason this is slow is because there's not that much demand for that level of automation in a helicopter like we see with cars. If there was consumer demand for an autonomous helicopter that could do NOE flying into sticky situations I think they could get there. It certainly wouldn't be overnight.

 

Then of course there's the holy grail of AI that surpasses human intelligence. Then sensors, servos, and all bets are off.

 

Mike

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